feat(site): showcase IDE workspace, diff/staging et services git distants

- WorkspaceShowcase.vue : maquette fidèle de la vue /workspace (arbre de
  fichiers + panneau commit staging/amend + diff coloré + terminal corrélé).
- RemoteGitSection.vue : connexions GitHub/GitLab/Gitea (chiffrées at-rest)
  + barre de progression de clone.
- 5 cartes features, pilier sécurité « Encrypted secrets », 3 FAQ, ancre nav.
- i18n EN/FR à parité ; meta description orientée IDE. Bump 0.2.0.

packages/site/src/App.vue

@@ -6,6 +6,8 @@ import HeroSection from './components/HeroSection.vue';
 import ProblemSection from './components/ProblemSection.vue';
 import FeaturesSection from './components/FeaturesSection.vue';
 import ShowcaseSection from './components/ShowcaseSection.vue';
+import WorkspaceShowcase from './components/WorkspaceShowcase.vue';
+import RemoteGitSection from './components/RemoteGitSection.vue';
 import WorkGroupsSection from './components/WorkGroupsSection.vue';
 import HowItWorksSection from './components/HowItWorksSection.vue';
 import SecuritySection from './components/SecuritySection.vue';
@@ -62,6 +64,8 @@ const glowStyle = {
       <ProblemSection />
       <FeaturesSection />
       <ShowcaseSection />
+      <WorkspaceShowcase />
+      <RemoteGitSection />
       <WorkGroupsSection />
       <HowItWorksSection />
       <SecuritySection />